Patellar tendinitis (jumper's knee)

Pronociceptive and antinociceptive neuromediators in patellar tendinopathy

BACKGROUND

The occurrence of nerve ingrowth and its relation to chronic tendon pain (tendinopathy) are still largely unknown. In healthy tendons, the innervation is confined to the paratenon, whereas the tendon proper is devoid of nerve fibers. In this study on the pathogenesis of tendinopathy, the authors examined sensory and sympathetic nerve fiber occurrence in the patellar tendon.

HYPOTHESIS

Nerve ingrowth and altered expression of sensory and sympathetic neuromediators play a major role in the pathophysiology of pain in patellar tendinopathy.

STUDY DESIGN

Case control study; Level of evidence, 3.

METHODS

Biopsies from the patellar tendon in patients with patellar tendinopathy (n = 10) were compared with biopsies from a control group (n = 10) without any previous or current knee symptoms compatible with patellar tendinopathy. The biopsies were stained immunohistochemically for sensory and autonomic nerve markers. The biopsies from the 2 groups were compared using subjective and semiquantitative methods.

RESULTS

Chronic painful patellar tendons exhibited increased occurrence of sprouting nonvascular sensory, substance P-positive nerve fibers and a decreased occurrence of vascular sympathetic nerve fibers, positive to tyroxin hydroxylase, a marker for noradrenaline.

CONCLUSION

The altered sensory-sympathetic innervation suggests a role in the pathophysiology of tendinopathy. Ingrowth of sprouting substance P fibers presumably reflects a nociceptive and maybe a proliferative role, possibly as reactions to repeated microtraumata, whereas the decreased occurrence of tyroxin hydroxylase may represent a reduced antinociceptive role. These findings could be used to develop targeted pharmacotherapy for the specific treatment of tendinopathy.

Is the chronic painful tendinosis tendon a strong tendon?: a case study involving an Olympic weightlifter with chronic painful Jumper's knee

The chronic painful tendinosis tendon is generally considered a degenerated and weak tendon. However, this has not been scientifically verified, and is to be considered a hypothesis. We present here a case study involving a high-level Olympic weightlifter with chronic painful patellar tendinosis who started heavy-weight training very early after successful treatment with sclerosing injections. A 25-year-old super heavy-weight (+105 kg) Olympic weightlifter with 9 months duration of severe pain (prohibiting full training) in the proximal patellar tendon, where ultrasound and Doppler showed a widened tendon with structural changes and neovascularisation, was given one treatment with ultrasound and Doppler-guided injections of the sclerosing agent polidocanol. The injections targeted the neovessels posterior to the tendon. The patient was pain-free after the treatment, and already after 2-weeks he started with heavy-weight training (240 kg in deep squats) to try to qualify for the Olympics. Additional very heavy training on training camps, most often without having any discomfort or pain in the patellar tendon, resulted in Swedish records and ninth place at the European Championships 17 weeks after the treatment. Despite beating the national records, he did not qualify for the Olympics. Ultrasound and Doppler follow-ups have shown only a few remaining neovessels, and little structural tendon changes. This case questions previous theories about the weak tendinosis tendon, and stresses the importance of studies evaluating tendon strength.

Current concepts in the management of tendon disorders

Primary disorders of tendons are common and constitute a high proportion of referrals to rheumatologists. Certain tendons are particularly vulnerable to degenerative pathology; these include the Achilles, patella, elements of the rotator cuff, forearm extensors, biceps brachi and tibialis posterior tendons. Disorders of these tendons are often chronic and can be difficult to manage successfully in the long term. Significant advances have been made in understanding the pathophysiology of these conditions. Histopathological evidence, together with advances in imaging techniques, has made us more appreciative of the degenerative (rather that inflammatory) nature of these conditions. Additionally the presence of neovascularization is now well-recognized in long-standing tendinopathy. We review the mechanical, vascular and developing neural theories that attempt to explain the aetiology of degenerative tendinopathy. We also explore theories of why specific tendons (such as the Achilles and supraspinatus tendons) are particularly prone to degenerative pathology. Traditionally, treatments have placed a heavy emphasis on anti-inflammatory strategies, which are often inappropriate. Recently, however, significant advances in the practical management of tendon disorders have been made. In particular the advent of 'eccentric loading' training programmes has revolutionized the treatment of Achilles tendinopathy in some patients. This concept is currently being extended to include other commonly injured tendons. Other current treatments are reviewed, as are potential future treatments.

Etiology of Patellar Tendinopathy in Athletes

Objective:

To review the etiology of patellar tendinopathy as it relates to clinical management of chronic patellar-tendon disease in athletes.

Data Sources:

Information was gathered from a MEDLINE search of literature in English using the key wordspatellar tendinitis, patellar tendonitis, patellar tendinosis, patellar tendinopathy,andjumper’s knee.

Study Selection:

All relevant peer-reviewed literature in English was reviewed.

Data Synthesis:

The etiology of patellar tendinopathy is multifactorial, incorporating both intrinsic and extrinsic factors. Age, muscle flexibility, training program, and knee-joint dynamics have all been associated with patellar tendinopathy. The roles of gender, body morphology, and patellar mobility in patellar tendinopathy are unclear.

Conclusions:

The pathoetiology of patellar tendinopathy is a complex process that results from both an inflammatory response and degenerative changes. There is a tremendous need for research to improve our understanding of the pathoetiology of patellar tendinopathy and its clinical management.

Neovascularisation and pain in jumper's knee: a prospective clinical and sonographic study in elite junior volleyball players

BACKGROUND

The nature of tendon neovascularisation associated with pain over time has not been studied.

OBJECTIVE

To prospectively study the patellar tendons in elite junior volleyball players.

METHODS

The patellar tendons in all students at the Swedish National Centre for high school volleyball were evaluated clinically and by ultrasonography (US) and Power Doppler (PD) sonography.

RESULTS

Altogether 120 patellar tendons were followed for 7 months. At inclusion, jumper's knee was diagnosed clinically in 17 patellar tendons. There were structural changes on US in 14 tendons, in 13 of which PD sonography showed neovascularisation. There were 70 clinically normal tendons with normal US and PD sonography, 24 clinically normal tendons with abnormal US but normal PD sonography, and nine clinically normal tendons with abnormal US and neovascularisation on PD sonography. At 7 month follow up, jumper's knee was diagnosed clinically and by US in 19 patellar tendons, in 17 of which there was neovascularisation. Three of nine clinically normal tendons with structural changes and neovascularisation at inclusion developed jumper's knee. Two of 24 tendons clinically normal at inclusion, with abnormal US but normal PD sonography, developed jumper's knee with abnormal US and neovascularisation on PD sonography. A total of 20 clinically normal tendons with normal US and PD sonography at inclusion developed structural tendon changes and 12 of these also developed neovascularisation.

CONCLUSIONS

The clinical diagnosis of jumper's knee is most often associated with neovascularisation in the area with structural tendon changes. The finding of neovessels might indicate a deterioration of the condition.

High prevalence of jumper's knee and sonographic changes in Swedish elite junior volleyball players compared to matched controls

BACKGROUND

Jumper's knee is a common and troublesome condition among senior volleyball players, but its prevalence among elite junior players compared to matched non-sports active controls is not known.

OBJECTIVE

To clinically, and by sonography, examine the patellar tendons in elite junior volleyball players (15-19 years) at the Swedish National Centre for volleyball and in matched controls.

METHODS

The patellar tendons in the 57 students at the Swedish National Centre for high school volleyball and in 55 age, height, and weight matched not regularly sports active controls were evaluated clinically and by grey scale ultrasonography (US) and power Doppler (PD) sonography.

RESULTS

There were no significant differences in mean age, height, and weight between the volleyball players and the controls. In the volleyball group, jumper's knee was diagnosed clinically and by US in 12 patellar tendons (10 male and two female). In 12/12 tendons, PD sonography demonstrated a neovascularisation in the area with structural tendon changes. In another 10 pain free tendons, there were structural tendon changes and neovessels. In the control group, no individual had a clinical diagnosis of jumper's knee. US demonstrated structural tendon changes in 11 tendons, but there was no neovascularisation on PD sonography.

CONCLUSIONS

A clinical diagnosis of jumper's knee, together with structural tendon changes and neovascularisation visualised with sonography, was seen among Swedish elite junior volleyball players but not in matched not regularly sports active controls. Structural tendon change alone was seen in 10% of the control tendons.

Patellar tendinopathy in athletes: current diagnostic and therapeutic recommendations

Formerly known as 'jumper's knee', patellar tendinopathy gives rise to considerable functional deficit and disability in recreational as well as professional athletes. It can interfere with their performance, often perseveres throughout the sporting career and may be the primary cause to end it. The diagnosis of patellar tendinopathy is primarily a clinical one but new imaging techniques, such as Doppler ultrasonography, may provide additional diagnostic value. Current therapeutic protocols are characterised by wide variability ensuing from anecdotal experience rather than evidence. Moreover, numerous reports in recent years have shattered previous doctrines and dogmatic belief on tendon overuse. Histopathological and biochemical evidence has indicated that the underlying pathology of tendinopathy is not an inflammatory tendinitis but a degenerative tendinosis. Consequently, pain in chronic patellar tendinopathy is not inflammatory in nature, but its exact origin remains unexplained. In pursuit of pathology- and evidence-based management, conservative therapy should be shifted from anti-inflammatory strategies towards a complete rehabilitation with eccentric tendon strengthening as a key element. If conservative management fails, surgery is opted for. However, considering the heterogeneity of surgical procedures and the absence of randomised studies, no conclusive evidence can be drawn from the literature regarding the effectiveness of surgical treatment for patellar tendinopathy. Parallel with the improved knowledge on the pathophysiology and pain mechanisms in patellar tendinopathy, new treatment strategies are expected to emerge in the near future.

Thermal microdebridement does not affect the time zero biomechanical properties of human patellar tendons

BACKGROUND

Thermal microdebridement for the treatment of chronic tendinopathy has recently been introduced. The effect of thermal microdebridement on the biomechanical properties of human tendons, however, remains unknown.

HYPOTHESIS

Thermal microdebridement does not affect the biomechanical properties of human patellar tendons in a cadaveric model at the time of initial treatment.

STUDY DESIGN

Controlled laboratory study.

METHODS

The central 15 mm of 12 matched, human (mean age, 71 years; 8 male, 4 female), fresh-frozen patellar tendons was divided into 3 equal 5-mm specimens. The treatment group (n = 12) underwent thermal microdebridement with a radiofrequency probe. A sham treatment group (n = 12) underwent insertion of a deactivated probe. The control group (n = 12) underwent no treatment. After treatment, each specimen was tested to failure in a servo-hydraulic materials testing machine at an elongation rate of 3 mm/s. One-way repeated measures analysis of variance was used to determine differences between groups.

RESULTS

No significant difference in ultimate stress at failure, elastic modulus, strain energy density, or strain at maximum load was found between the groups. The ultimate stress at failure for the treatment, sham, and control groups was 61.0, 66.7, and 63.0 MPa, respectively (P = .653), and the strain at maximum load was 0.12, 0.11, and 0.09, respectively (P = .279).

CONCLUSIONS

Thermal microdebridement does not affect the biomechanical properties of cadaveric human patellar tendons at the time of initial treatment.

CLINICAL RELEVANCE

It may be safe to proceed with aggressive rehabilitation after thermal microdebridement of the patellar tendon. However, the results in this cadaveric model should be interpreted with caution. Additional studies using an in vivo model will be required to completely assess the effects of thermal microdebridement on the biomechanical properties of human patellar tendons.

Patellar tendinopathy

Patellar tendinopathy is a common and serious condition in athletes. Although there have been many advances in the understanding of the histopathology, imaging, and surgical outcomes in this condition in the past decade, successful management of athletes with patellar tendinopathy remains a major challenge for both the practitioner and patient. There is a definite need for further prospective studies into etiological factors and randomized controlled trials into treatment choices.

Performance characteristics of volleyball players with patellar tendinopathy

BACKGROUND

Patellar tendinopathy is assumed to result from chronic tendon overload. There may be a relationship between tendon pain and jumping ability.

HYPOTHESIS

There is no difference in performance characteristics between volleyball players with patellar tendinopathy and those without.

STUDY DESIGN

Prospective cohort study.

METHOD

We examined the performance of the leg extensor apparatus in high-level male volleyball players with patellar tendinopathy (N = 24) compared with a control group (N = 23) without knee symptoms. The testing program consisted of different jump tests with and without added load, and a composite jump score was calculated to reflect overall performance.

RESULTS

The groups were similar in age, height, and playing experience, but the patellar tendinopathy group did more specific strength training and had greater body weight. They scored significantly higher than the control group on the composite jump score (50.3 versus 39.2), and significant differences were also observed for work done in the drop-jump and average force and power in the standing jumps with half- and full-body weight loads.

CONCLUSIONS

Greater body weight, more weight training, and better jumping performance may increase susceptibility to patellar tendinopathy in volleyball players.

Cross-sectional outcome analysis of athletes with chronic patellar tendinopathy treated surgically and by extracorporeal shock wave therapy

OBJECTIVE

To compare the outcome of chronic patellar tendinopathy treated surgically and by extracorporeal shock wave therapy.

DESIGN

Cross-sectional outcome analysis.

SETTING

University Hospital Pellenberg, Leuven, Belgium.

PATIENTS AND INTERVENTIONS

Of a total of 27 patients (28 knees) with chronic patellar tendinopathy, 13 were treated surgically, and 14 (15 knees) received extracorporeal shock wave therapy.

MAIN OUTCOME MEASUREMENTS

Functional outcome questionnaire: Victorian Institute of Sport Assessment score, Visual Analog Scale, and Roles and Maudsley classification.

RESULTS

At an average of 6 months of follow-up, the mean Victorian Institute of Sport Assessment and Visual Analog Scale scores for the extracorporeal shock wave therapy group were 78.8 +/- 28.7 and 9 +/- 2, respectively, which improved to 83.9 +/- 28.6 and 9 +/- 2, respectively, at 22.1 months. The surgery group scored 70.7 +/- 22.2 points on the Victorian Institute of Sport Assessment at an average of 26.3 months of follow-up (p = 0.41 and p = 0.18) and 8 +/- 3 on the Visual Analog Scale (p = 0.14). In the extracorporeal shock wave therapy group, 5 (33%) patients rated their pain status at 22.1 months as excellent, 5 (33%) as good, 2 (13%) as fair, and 2 (13%) as poor. In the surgery group, 4 (33%) evaluated the result as excellent, 3 (25%) as good, 3 (25%) as fair, and 2 as poor (17%).

CONCLUSIONS

Extracorporeal shock wave therapy shows a comparable functional outcome to surgery in a cross-sectional analysis of patients with chronic proximal patellar tendinopathy resistant to conservative treatment.

Is impingement the cause of jumper's knee? Dynamic and static magnetic resonance imaging of patellar tendinitis in an open-configuration system

BACKGROUND

Chronic overload is considered the main cause of patellar tendinitis, but it has been postulated that impingement of the inferior patellar pole against the patellar tendon during knee flexion could be responsible.

HYPOTHESIS

The role of the patellar pole in patellar tendinitis can be determined by dynamic magnetic resonance imaging.

STUDY DESIGN

Case-control study.

METHODS

We compared 19 knees with patellar tendinitis and 32 asymptomatic knees of age-matched subjects using an open-configuration magnetic resonance imaging system. Dynamic sagittal images were obtained from full extension to 100 degrees of flexion with and without activation of the quadriceps muscle. The following measurements were made from the images: tendon-patella angle, anteroposterior diameter of the tendon, signal difference-to-noise ratio, the shape of the inferior patellar pole, and the location of the patellar tendon insertion.

RESULTS

The tendon-patella angle was not significantly different between groups at any flexion angle, with or without quadriceps muscle activation. The insertion site of the patellar tendon differed significantly but not the shape of the inferior pole of the patella. The volume and the signal difference-to-noise ratio of zones of increased intratendinous signal as well as the anteroposterior diameter of the proximal patellar tendon were increased in symptomatic knees.

CONCLUSIONS

The relationship between the patella and the patellar tendon was identical in both groups; therefore, chronic overload seems to be a major cause of patellar tendinitis.

Intrinsic risk factors for the development of patellar tendinitis in an athletic population. A two-year prospective study

Retrospective studies have suggested various factors that might cause a disposition to develop patellar tendinitis, but no prospective data exist to determine any relationships. The purpose of this study was to determine the intrinsic risk factors for the development of patellar tendinitis in an athletic population. Before the study, 138 male and female students of physical education were evaluated for anthropometric variables, leg alignment characteristics, and muscle tightness and strength parameters. During the 2-year study, 19 of the 138 students developed patellar tendinitis. In all cases the diagnosis was confirmed by the presence of a hypoechogenic nodular lesion in the proximal region of the patellar tendon. Univariate and stepwise discriminant function analyses were performed comparing the various measurements. These analyses revealed that the only significant determining factor was muscular flexibility, with the patellar tendinitis patients being less flexible in the quadriceps and hamstring muscles (P < 0.05). The results of this study demonstrate that lower flexibility of the quadriceps and hamstring muscles may contribute to the development of patellar tendinitis in an athletic population. Therefore, the prevention of this condition in athletes should be focused on screening for and treating poor quadriceps and hamstring muscle flexibility.

Reproducibility and clinical utility of tendon palpation to detect patellar tendinopathy in young basketball players. Victorian Institute of Sport tendon study group

BACKGROUND

Palpation is an important clinical test for jumper's knee.

OBJECTIVES

To (a) test the reproducibility of palpation tenderness, (b) evaluate the sensitivity and specificity of palpation in subjects with clinical symptoms of jumper's knee, and (c) determine whether tenderness to palpation may serve as a useful screening test for patellar tendinopathy. The yardstick for diagnosis of patellar tendinopathy was ultrasonographic abnormality.

METHODS

In 326 junior symptomatic and asymptomatic athletes' tendons, palpation was performed by a single examiner before ultrasonographic examination by a certified ultrasound radiologist. In 58 tendons, palpation was performed twice to test reliability. Tenderness to palpation was scored on a scale from 0 to 3 where 0 represented no pain, and 1, 2, and 3 represented mild, moderate, and severe tenderness respectively.

RESULTS

Patellar tendon palpation was a reliable examination for a single examiner (Pearson r = 0.82). In symptomatic tendons, the positive predictive value of palpation was 68%. As a screening examination in asymptomatic subjects, the positive predictive value of tendon palpation was 36-38%. Moderate and severe palpation tenderness were better predictors of ultrasonographic tendon pathology than absent or mild tenderness (p<0.001). Tender and symptomatic tendons were more likely to have ultrasound abnormality than tenderness alone (p<0.01).

CONCLUSIONS

In this age group, palpation is a reliable test but it is not cost effective in detecting patellar tendinopathy in a preparticipation examination. In symptomatic tendons, palpation is a moderately sensitive but not specific test. Mild tenderness in the patellar tendons in asymptomatic jumping athletes should be considered normal.

Patellar tendinopathy in athletes. Outcome of nonoperative and operative management

We report the results of nonoperative and operative management of patellar tendinopathy in 42 athletes with Blazina stage 2 (26 patients) or stage 3 (16 patients) patellar tendinopathy. All patients were initially managed nonoperatively with nonsteroidal antiinflammatory drugs, physical therapy, and a progressive rehabilitation program based on isometric exercises, stretching, and eccentric exercises. After 6 months, 33 patients showed symptomatic improvement and were able to resume their sports. In nine patients with Blazina stage 3 tendinopathy, nonoperative measures failed, and surgery was performed. Operative treatment consisted of removal of the degenerated areas of the tendon, multiple longitudinal tenotomies, and drilling of the lower pole of the patella at the site of tendon attachment. Histologic examination of the excised tendon tissue showed areas of necrosis and mucoid degeneration, and alterations of the bone-tendon junction. After a mean follow-up of 4.8 years, clinical results were excellent or good in all patients. In the group treated nonoperatively, results were better in the patients who had stage 2 tendinopathy than in those with stage 3.

Open and arthroscopic patellar tenotomy for chronic patellar tendinopathy. A retrospective outcome study. Victorian Institute of Sport Tendon Study Group

Chronic patellar tendinopathy often requires surgical treatment. We compared the outcomes in 25 subjects (29 tendons) who had had open patellar tenotomy and 23 subjects (25 tendons) who had had arthroscopic patellar tenotomy at a mean follow-up of 3.8 and 4.3 years, respectively. At follow-up, outcomes in the open and arthroscopic groups were as follows: 1) symptomatic benefit was seen in 81% of open and 96% of arthroscopic tenotomy patients, 2) sporting success was seen in 54% of open and 46% of arthroscopic tenotomy patients, 3) median time to return to preinjury level of activity was 10 months for open and 6 months for arthroscopic tenotomy patients, and 4) median Victorian Institute of Sport Assessment score at follow-up was 88 for open and 77 for arthroscopic tenotomy patients. There were no significant differences between groups for all outcomes. The appearance of the tendon on sonography remained abnormal in over 70% of subjects at follow-up, and sonographic appearance did not correlate with clinical outcome. Thus, arthroscopic patellar tenotomy was as successful as the traditional open procedure. Both procedures provided virtually all subjects with symptomatic benefit, but only about half the subjects who underwent either open or arthroscopic patellar tenotomy were competing at their former sporting level at follow-up.

Arthroscopic treatment of infrapatellar tendonitis

Infrapatellar tendonitis is a chronic overload lesion in the patellar ligament at the attachment to the lower pole of the patella. This lesion is found primarily in athletes who participate in jumping sports. Magnetic resonance imaging or ultrasound can show the extent of tendon pathology. Patellar tendonitis is treated with modification of activities, medications, and therapy. When conservative measures fail, operative debridement has been recommended. Previous reports have described a technique of open debridement of the patellar tendon, followed by an extended period of rehabilitation before returning to sports. Two athletes with persistent infrapatellar tendonitis were treated with an arthroscopic debridement. Both athletes returned to full activities without restrictions within 8 weeks of surgery. Arthroscopic treatment of infrapatellar tendonitis has not been previously described. This technical note describes the technique and two case reports of the arthroscopic treatment of infrapatellar tendonitis.

Imaging in sports-medicine--knee

Since the last decade, the introduction of Magnetic Resonance Imaging has provided a powerful new tool for the clinician to diagnose sports-related knee injuries. The main objective of this paper is to familiarise the relevant specialists with the proven clinical indications and semiology of MRI of the knee. At the present time, the knee joint is the area in which the advantages of MRI are most spectacularly apparent. The MR appearances of meniscal tears in particular, are first discussed in detail, referring to recent literature and personal experience based on more than ten thousands MR examinations of traumatic knees. Also the mechanisms of injuries and the most commonly involved sports are described. The precise types of meniscal lesions, as visualised at arthroscopy, are abundantly illustrated on MR images: e.g., bucket-handle, radial and horizontal cleavage tears, meniscocapsular separations, discoid menisci and meniscal cysts. We discuss the numerous pitfalls due to neighbouring anatomical structures as well as non clinically or surgically significant intrameniscal hypersignals in athletes. Towards other imaging techniques, MRI is particularly suited for the diagnosis of ligamentous injuries, especially the cruciate ligaments. We develop the currently used direct and indirect signs of rupture, the diagnostic difficulties related to the age of trauma and the detection of associated lesions. Sport-induced tendinous and bursal pathology is another interesting indication of MRI, not only lesions of the more superficial extensor tendons but also the pes anserinus or hamstring tendons. We finally treat the recent developments of MRI in assessment of cartilage, subchondral and medullary bone disorders of traumatic or microtraumatic origin.

Imaging of tendons--adaptation, degeneration, rupture

Tendon imaging is mainly performed with ultrasonography (US) and magnetic resonance imaging (MRI) and has been improved within the last years because of technical advancements and a better understanding of tendon pathology. Several concepts concerning the etiology and the course of tendon diseases have influenced image interpretation and vice versa. Adaptive mechanisms within the tendon tissue against stress can be observed mainly on histologic specimens and not macroscopically or with in-vivo imaging. Degeneration may occur in the form of tendinitis, peritendinitis, enthesitis, or myotendinal junction abnormality. Distinct imaging findings exist for most of these forms. Many concepts that have been developed to explain tendon degeneration have been applied on virtually all tendons in the human body. They can be grouped into those which focus on hypovascularization, on biomechanical overload, and on degeneration secondary to other underlying disease. Tendon rupture seems, in many cases, to be the final stage of tendinitis. From this point of view, imaging may be used to predict the risk of tendon rupture together with other intrinsic and with extrinsic parameters. These considerations result in the concept of the "vulnerable zone" and of the "critical phase" in which tendon ruptures may predominantly occur.

Anteromedial tibial tubercle transfer in patients with chronic anterior knee pain and a subluxation-type patellar malalignment

We performed a prospective analysis of 29 Fulkerson anteromedial tibial tubercle transfers in patients with chronic anterior knee pain. The average followup was 32 months (range, 25 to 44). Fourteen patients (Group 1) had subluxation-type malalignment (congruence angle > 20 degrees, tilt angle > 8 degrees) and were treated with an isolated anteromedial tibial tubercle transfer. Fifteen patients (Group 2) had combined subluxation and tilt malalignment (congruence angle > 20 degrees, tilt angle < 8 degrees) and underwent anteromedial tibial tubercle transfer combined with a lateral release. Pre- and postoperative evaluations included clinical and radiographic examinations, Lysholm and Kujala patellofemoral scores, and standing-alignment computed tomography scans in 15 degrees of flexion taken transversely at the midpatellar. In all but one patient a dramatic improvement in Lysholm and Kujala scores was noted. The congruence angle improved in all patients except one, with an average improvement of 16 degrees in Group 1 and of 14 degrees in Group 2. The tilt angle remained relatively unchanged (change, -0.5 degree) in Group 1, but it improved by 11 degrees in Group 2. We conclude that an isolated anteromedial tibial tubercle transfer can consistently improve patellar subluxation and, when combined with a lateral release, can improve patellar subluxation and tilt, resulting in improved functional scores for patients with chronic anterior knee pain.

Recalcitrant patellar tendinitis. Magnetic resonance imaging, histologic evaluation, and surgical treatment

Magnetic resonance imaging findings and the results of surgical treatment and histologic evaluation of 11 knees in 9 athletes with recalcitrant patellar tendinitis are reported. All of the athletes had no improvement with traditional nonoperative treatment and all had abnormal magnetic resonance imaging findings consistent with chronic patellar tendinitis. Surgical exploration and debridement were performed on the 11 knees by the same surgeon. With a minimum followup of 1 year, 7 of the 11 knees had excellent results, 3 had good results, and 1 had a poor result. Histologic evaluation of the debrided tissue was consistent with "angiofibroblastic tendinosis," which correlated with the abnormal preoperative magnetic resonance imaging findings in the proximal third of the infrapatellar tendon. This study correlated histologic findings with magnetic resonance imaging findings and shows that in selected patients excellent results can be achieved with surgical treatment of recalcitrant patellar tendinitis or "jumper's knee."

Relationship between symptoms of jumper's knee and the ultrasound characteristics of the patellar tendon among high level male volleyball players

This study assessed the ultrasound characteristics of the patellar tendon in two groups of volleyball players, one group without knee symptoms and one group with symptoms of jumper's knee. Of 47 male elite players, 25 were diagnosed to have current and seven to have had previous symptoms of jumper's knee, as determined by clinical examination. Since some players had bilateral problems, there were 34 knees with current problems and nine with previous problems. Seven of the 30 knees with a clinical diagnosis of jumper's knee in the patellar tendon had normal ultrasound findings, and ultrasound changes believed to be associated with jumper's knee (tendon thickening, echo signal changes, irregular paratenon appearance) were observed in 12 of 51 knees without symptoms. Specific ultrasound findings such as paratenon changes, hypoechoic zones or pathological tendon thickness proximally did not correlate significantly with the degree or the duration of symptoms. This study suggests that the specificity and sensitivity of ultrasonography is low in the evaluation of patients with mild symptoms of jumper's knee.

Knee joint dynamics predict patellar tendinitis in elite volleyball players

We quantified the lower extremity dynamics developed during the volleyball spike and block jumps to find out if predictive relations exist between jump dynamics and patellar tendinitis. Lower extremity movement biomechanics were analyzed for 10 members of the 1994 Canadian Men's National Volleyball Team (all right-handed hitters). Based on physical examination, 3 of the 10 players had patellar tendon pain associated with patellar tendinitis at the time of testing. In masked biomechanical and logistic regression analyses, we discovered that the vertical ground-reaction force during the take-off phase of both spike and block jumps was a significant predictor of patellar tendinitis-correctly predicting the presence or absence of patellar tendinitis in 8 of 10 players. Deepest knee flexion angle (during landing from the spike jump) predicted 10 of 10 cases correctly for the left knee. The external tibial torsional moment (during the takeoff for the right knee with the spike jump and for the left knee with the block jump) was also a significant predictor of tendinitis. In these players, the likelihood of patellar tendon pain was significantly related to high forces and rates of loading in the knee extensor mechanism, combined with large external tibial torsional moments and deep knee flexion angles.

Characteristics of the leg extensors in male volleyball players with jumper's knee

The aim of the present study was to characterize the performance ability of the leg extensor apparatus in a group of athletes with jumper's knee and to compare the results with those of a matched control group without knee symptoms. Patient and control groups (12 players in each) were selected from a population of 141 well-trained male Norwegian volleyball players, of which 55 (39%) satisfied the diagnostic criteria for jumper's knee. The testing program consisted of a standing jump, a countermovement jump, a 15-second rebound jump test, a standing jump with a 20-kg load, and a standing jump with a load corresponding to one-half of the subject's body weight. Jump height and power were measured using a contact mat connected to an electronic timer. The test results of the patient group were significantly higher than those of the control group for the countermovement jump (15% increase), power during rebound jump (41%), work done in standing jump (12%) and countermovement jump (22%), and the difference between countermovement jump and standing jump (effect of adding eccentric component). Athletes with jumper's knee demonstrated better performance in jump tests than uninjured athletes, particularly in ballistic jumps involving eccentric force generation.

Treatment of infrapatellar Tendinitis: A Combination of Modalities and Transverse Friction Massage versus Iontophoresis

The purpose of this study was to compare an established protocol of modalities and transverse friction massage (MOD & TFM) with iontophoresis of dexamethasone and lidocaine (IONTO) in the treatment of patients with infrapatellar tendinitis. Thirty cases with infrapatellar tendinitis were randomly assigned to either the MOD & TFM or the IONTO intervention. Subjects still symptomatic after six sessions of intervention received the alternate treatment protocol. Four measures were used to assess patient status: a functional index questionnaire, a visual analog pain scale, a rating of tenderness with palpation of the involved tendon, and the number of step-ups needed to elicit pain. In response to the MOD & TFM intervention, only the number of step-ups performed to elicit pain showed significant improvement. All status measures improved significantly with the IONTO intervention. The results suggest that iontophoresis may be more effective and efficient in decreasing pain, reducing inflammation, and promoting healing in patients with infrapatellar tendinitis.

Surgical treatment of patellar tendinitis

Patellar tendinitis is an overuse syndrome affecting the origin of the patellar tendon and its underlying part. Ultrasonography is useful to investigate tendinous pathology. It describes the anatomical lesions and their extent. Surgical excision of irreversible lesions, demonstrated on ultrasonography, is a logical attitude which provides good results.

Partial rupture of the patellar ligament

Eighty-one patients with 91 partial ruptures of the patellar ligament verified by ultrasonography were treated conservatively with a standardized training program based on the principles of eccentric loading. The partial ruptures were quantified by measuring the length of the hypoechoic lesion using ultrasonography in longitudinal projection. The partial ruptures were then divided into three groups: Grade I (less than 10 mm), Grade II (10 to 20 mm), and Grade III (greater than 20 mm). The results after the training program were significantly better in Grade I ruptures than in Grades II and III. The overall need for surgery was 29.6%: highest in Grade III ruptures (38.5%) and lowest in Grade I ruptures (6.6%). The outcome of conservative management, as well as the need for surgery of partial ruptures of the patellar ligament, may to some extent be predicted by the use of ultrasonography.

Patellar Tendonitis: Jumper's Knee

Patellar tendonitis is a common pathology seen in athletes involved in activities requiring forceful eccentric muscle contractions or repeated flexion and extension of the knee. This article reviews the related anatomy, biomechanics, mechanism of injury, and diagnosis of patellar tendonitis. It also presents several treatment approaches and suggestions to help identify athletes at risk.

Partial rupture of the patellar ligament. Results after operative treatment

Partial rupture of the patellar ligament, also known as jumper's knee, is defined as a repetitive overload lesion at the bone-ligament junction at the lower patellar pole. It is found mainly in athletes and is caused either by microruptures or partial macroruptures of the proximal part of the ligament. The abnormal anatomical lesion is focal degeneration, microruptures and macroruptures, and devitalized tissue at the insertion of the patellar ligament. Proliferation and neovascularization are often found, as well as degeneration and incomplete tissue healing. Surgical treatment is indicated only if a prolonged and well-supervised conservative treatment program fails. We operated on 78 patients with jumper's knee, by carefully removing the abnormal tissue from the ligament. At follow-up examination, 71 of 78 patients had excellent or good functional results and complete resumption of sports activities. Objective measurements of thigh muscle strength using a Cybex II dynamometer correlated with the functional results at a low angular velocity.

Ultrasonography in the detection of partial patellar ligament ruptures (jumper's knee)

The diagnostic performance of ultrasonography (US) in the detection of partial ruptures in the proximal part of the patellar ligament (jumper's knee) was studied. A total of 81 athletes with chronic localized pain suggestive of jumper's knee underwent US examination, and 25 of these received surgical treatment. Of 25 proven partial tendon ruptures at surgery, US correctly indicated the diagnosis in all cases. A cone-shaped, poorly echogenic area exceeding 0.5 cm in length in the center of the patellar tendon in combination with its localized thickening proved to be a reliable indicator of jumper's knee. One case was a true-negative. No false-negative or false-positive case was observed. Soft-tissue radiography in 14 cases showed a localized swelling but did not detect intratendinous soft-tissue abnormalities. US is the method of choice for the evaluation of jumper's knee, as it is cheap, non-invasive, repeatable, and accurate.

Ultrasound, computed tomography and magnetic resonance imaging in patellar tendinitis

This prospective study describes the ultrasound, computerized tomography and magnetic resonance imaging findings in 16 cases of patellar tendinitis. In all cases tendon enlargement and reduced echogenicity were visible on ultrasound. Computerized tomography demonstrated enlargement of the tendon with reduced attenuation of the central portion. Magnetic resonance imaging showed focal tendon enlargement in all patients with high signal lesions in 88% of cases. This study has shown that patellar tendinitis may be identified with all three modalities. Ultrasound is recommended as the initial investigation in the assessment of patients with this condition.

Knee injuries in volleyball

The knee is the most frequent site of injury in volleyball players. More than 40% of high level players suffer overuse injuries during this activity; this particularly painful syndrome is caused by the amount of jumping typical in volleyball play, and in its training which aims at strengthening the quadriceps muscle. In volleyball players the extensor apparatus is subject to continuously high stress and the bone tendon junction, being the weakest point, is susceptible to lesion. The prevention and treatment of 'jumper's knee' requires a high degree of cooperation among trainers, doctors and athletes. Although volleyball is a sport without contact between players, traumatic acute injuries are more frequent and more serious than would be expected. It is therefore important to emphasise that volleyball must be considered among the high risk sports that expose the knee not only to twisting, but also to contact with other players. Generally, the lesions are caused by frequent jumps with loss of balance and a consequent 'one-footed' landing. There is no specific method of preventing knee instability. Accurate diagnoses, rest and rapid surgical treatment after the first injury are recommended in order to avoid chronic knee instability with subsequent meniscal lesions and post-traumatic osteoarthritis.

Jumper's Knee

Jumper's knee is a common manifestation seen in the athletic population, resulting from overuse of the knee extensor mechanism. The purpose of this article is to review the literature associated with jumper's knee, in the hope that it may benefit the physical therapist's understanding and management of this condition. The pertinent anatomical, biomechanical, and physiological aspects will be briefly reviewed. Clinical findings, methods of conservative treatment, and a proposed method of prevention will be presented. J Orthop Sports Phys Ther 1989;11(4):137-141.

Jumper's knee and ultrasonography

Twenty-five patients, aged between 15 and 45 years old, who were athletically active, presented with jumper's knee (patellar tendinitis). By use of ultrasonographic examination, new and precise information was obtained that benefited the diagnosis, choice of treatment, and monitoring of the evolution of jumper's knee in our patients. In 18 of the 25 patients, only 1 knee was affected; in 7 of the patients, both knees were affected, thus making a total of 32 painful tendons. These 25 patients were compared with a control group of 15 healthy, athletically active subjects between the ages of 25 and 35 years old. In all of the 32 painful tendons, ultrasonographic anomalies were observed: thickening or swelling of the tendon (15 knees) appeared in acute cases; a heterogeneous structure of the tendon (24 knees); and thickening and irregularities of the tendinous envelope (8 knees). The 15 acute patients all responded to classic conservative treatment including physical therapy and electrotherapy. Four of the remaining 10 patients were treated successfully with various conservative treatments, including deep transverse friction massage with ice. The other six patients were treated surgically, with tenolysis and "carding" of the patellar tendon. In one patient, this procedure failed, and 12 months later a second operation was performed, in which the distal pole of the patella was resected and the patellar tendon reinserted into bone. Recovery was uneventful. Now, at least 2 years after treatment, all of the patients consider themselves healed.

Computed tomography and ultrasound imaging of jumper's knee-patellar tendinitis

We present nine cases of this relatively unreported condition affecting the patellar ligament in athletes. A comparison between ultrasound and computed tomography of this lesion, shows that whilst neither modality gives false positives, ultrasound is capable of greater distinction between the histological abnormalities confirmed at surgery.

The use of thermography for the diagnosis and management of patellar tendinitis

Computerized thermography was used to evaluate 17 patients diagnosed with patellar tendinitis. The intent of this study was to determine if a specific patellar tendinitis thermal pattern could be distinguished using infrared thermography. A specific thermal abnormality was found over the patellar tendon in 14 subjects (78%). Twelve subjects showed focal "hot" spots, while two showed focal "cold" spots. The thermal abnormalities appeared as specific focal areas directly overlaying the patellar tendon, without disruption to the thermal pattern of the remaining peripatellar regions. The thermal gradient slope over the patellar tendon was greater in symptomatic knees. Five subjects returned 2-4 weeks later for follow-up thermographic examination. Among the follow-up subject group, changes in thermal asymmetry correlated with changes in symptoms 80% of the time. Computerized thermography appears useful as a noninvasive, objective method of detecting inflammation of the soft tissues about the patellar tendon, and also helps to differentiate this disorder from other knee pathologies. J Orthop Sports Phys Ther 1987;9(4):132-140.